For conducting girdling experiments

Options

A. the cortex is removed
B. the cortex and primary phloem and removed
C. all tissues upto secondary xylem are removed
D. none of the above

Answer

To solve the question about conducting girdling experiments, we need to understand what girdling is and what it entails.

### Step-by-Step Solution:

1. **Understand Girdling**: Girdling is a technique used to study the transport of nutrients and water in plants. It involves removing a ring of bark from around the trunk of a tree or woody plant.

2. **Identify the Components Involved**: The bark of the tree contains the phloem, which is responsible for the transport of food (sugars) produced by photosynthesis. The xylem, located beneath the phloem, is responsible for the transport of water and minerals.

3. **Determine What is Removed**: In a girdling experiment, the removal of the bark (which includes the phloem) is essential. Depending on the depth of the girdle, it may also involve the removal of some surrounding tissues.

4. **Analyze the Options**:
- **Option A**: The cortex is removed. (Partially correct, but doesn't specify the phloem)
- **Option B**: The cortex and primary phloem are removed. (More accurate as it includes phloem)
- **Option C**: The tissue up to secondary xylem is removed. (This is the most accurate as it indicates that the phloem and some surrounding tissues are removed)
- **Option D**: None of the above. (Incorrect as there are valid options)

5. **Select the Correct Answer**: Based on the analysis, the correct answer is **Option C**, as it indicates that all tissues up to the secondary xylem are removed, which is necessary for the girdling experiment to demonstrate the role of phloem in translocation.

### Final Answer:
**Option C: The tissue up to secondary xylem are removed.**

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